Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

OBJECTIVE To evaluate the cost-effectiveness of bevacizumab combined with erlotinib in the first-line treatment of advanced EGFR mutant non-squamous non-small cell lung cancer （NSCLC） from the perspective of China’s health system. METHODS A dynamic Markov model was established based on BEVERLY study data， with a cycle of 3 weeks， a research deadline until 99% of patients die， and an annual discount rate of 5%. The model outputs were total cost， quality-adjusted life year （QALY）， and incremental cost-effectiveness ratio （ICER）. Taking 3 times China’s per capita gross domestic product （GDP） in 2023 as the willingness-to-pay （WTP） threshold， the cost-utility analysis was used to evaluate the cost-effectiveness of bevacizumab combined with erlotinib （observation group） versus erlotinib alone （control group） in the first-line treatment of advanced EGFR mutant non-squamous NSCLC， and the single factor sensitivity analysis and probability sensitivity analysis were used to verify the robustness of the basic analysis results. RESULTS The results of the basic analysis showed that compared with the erlotinib therapy plan， ICER of bevacizumab combined with erlotinib was 1 452 243.01 yuan/QALY， which was more than 3 times China’s per capita GDP in 2023 （268 074 yuan/QALY） as the WTP threshold， indicating that bevacizumab combined with erlotinib was not cost-effective. The results of single factor sensitivity analysis showed that the cost of bevacizumab， the utility value of progression-free survival and progressed disease status had a great influence on the results. The results of probability sensitivity analysis showed that when the WTP threshold was 1 740 000 yuan/QALY， the probability of cost-effective of bevacizumab combined with erlotinib plan was 50%. CONCLUSIONS Compared with erlotinib alone， bevacizumab combined with erlotinib is not cost-effective in the first-line treatment of advanced EGFR mutant non-squamous NSCLC， when using 3 times China’s per capita GDP in 2023 as the WTP threshold.

OBJECTIVE To evaluate the cost-effectiveness of bevacizumab combined with erlotinib in the first-line treatment of advanced EGFR mutant non-squamous non-small cell lung cancer （NSCLC） from the perspective of China’s health system. METHODS A dynamic Markov model was established based on BEVERLY study data， with a cycle of 3 weeks， a research deadline until 99% of patients die， and an annual discount rate of 5%. The model outputs were total cost， quality-adjusted life year （QALY）， and incremental cost-effectiveness ratio （ICER）. Taking 3 times China’s per capita gross domestic product （GDP） in 2023 as the willingness-to-pay （WTP） threshold， the cost-utility analysis was used to evaluate the cost-effectiveness of bevacizumab combined with erlotinib （observation group） versus erlotinib alone （control group） in the first-line treatment of advanced EGFR mutant non-squamous NSCLC， and the single factor sensitivity analysis and probability sensitivity analysis were used to verify the robustness of the basic analysis results. RESULTS The results of the basic analysis showed that compared with the erlotinib therapy plan， ICER of bevacizumab combined with erlotinib was 1 452 243.01 yuan/QALY， which was more than 3 times China’s per capita GDP in 2023 （268 074 yuan/QALY） as the WTP threshold， indicating that bevacizumab combined with erlotinib was not cost-effective. The results of single factor sensitivity analysis showed that the cost of bevacizumab， the utility value of progression-free survival and progressed disease status had a great influence on the results. The results of probability sensitivity analysis showed that when the WTP threshold was 1 740 000 yuan/QALY， the probability of cost-effective of bevacizumab combined with erlotinib plan was 50%. CONCLUSIONS Compared with erlotinib alone， bevacizumab combined with erlotinib is not cost-effective in the first-line treatment of advanced EGFR mutant non-squamous NSCLC， when using 3 times China’s per capita GDP in 2023 as the WTP threshold.

Objective    To discuss the efficacy of type Ⅱ hybrid aortic arch repair for type A aortic dissection in patients of different age groups. Methods    We retrospectively analyzed the clinical data of 126 patients with type A aortic dissection admitted to the Fuwai Hospital between January 2016 and December 2018, including 78 (61.9%) males and 48 (38.1%) females, with an average age of 61.8±6.9 years. The patients were divided into an elderly group (≥60 years, n=82) and a non-elderly group (<60 years, n=44). The preoperative, intraoperative and postoperative data of patients in the two groups were compared. Results    The age between the elderly and non-elderly group was significantly different (65.9±4.1 years vs. 54.3±4.1 years, P<0.010), and no significant difference was found between the two groups in other preoperative baseline data. There were 6 (4.8%) patients of early death, 3 (2.4%) patients of stroke and 2 (1.6%) patients of paralysis. A total of 194 stents were implanted, and the average dimeter of the stents was 33.6±1.8 mm and the average length was 199.0±6.7 mm. The non-elderly group had shorter mechanical ventilation time (31.9±41.7 h vs. 61.0±89.2 h, P=0.043) and ICU stay time (77.8±51.4 h vs. 143.1±114.4 h, P<0.001) than the elderly group. There was no significant difference in in-hospital mortality rate, reoperation rate or survival rate between the two groups (P>0.05). Follow-up time was 1-43 (22.6±10.8) months, and 3 patients were lost. There were 104 (82.5%) patients of complete thrombus formation of false lumen in stent and endoleak was reported in 11 (9.2%) patients. Conclusion    Type Ⅱ hybrid aortic arch repair offers an alternative approach to acute type A aortic dissection with acceptable early and mid-term clinical effects. The non-elderly patients have a similar early treatment effect to the elderly patients, but have a better mid-term outcome.

OBJECTIVE:To provide reference for rational drug use in clinic and nosocomial infection control. METHODS:Acinetobacter baumannii(AB)were collected from our hospital during Jan. 2014-Jun. 2017. Drug sensitivity tests were conducted by using K-B method and MIC method. Drug-resistance genes of multidrug-resistant Acinetobacter baumannii(MDR-AB)were amplified by PCR,and compared with GenBank database by using Blast comparison. RESULTS:A total of 1 758 strains of AB were detected,and mainly came from sputum and throat swab(65.24%),followed by urine(18.49%). These infected patients were mainly distributed in the departments of ICU(38.51%)and respiratory medicine(24.00%),respectively. Drug resistance of clinical isolated AB to most commonly used antibiotics were more than 40%,such as compound sulfamethoxazole,piperacillin sodium and tazobactam sodium,gentamicin,cefepime,levofloxacin,minocycline,imipenem,etc.;it had increased year after year. Drug resistance to colistin was lower than 5% and decreased year by year.A total of 673 strains of MDR-AB were detected, and detection rates were 22.77%,29.82%,52.09%,54.33%,respectively.Among 110 strains of MDR-AB,detection rates of TEM, AmpC,IMP,VIM,OXA-23,OXA-24,OXA-51,aac(6′)-Ⅰ,aac(3)-Ⅰ,ant(3″)-Ⅰ,anmA,gyrA,parC gene were 97.27%, 91.82%,49.09%,12.73%、90.91%,12.73%,98.18%,34.55%,60.91%,89.09%,87.27%,77.27%,82.73%,respectively. Results of Blast comparison showed that point mutation occurred in 83rd and 121st base of gyrA gene,144th base of parC gene. CONCLUSIONS:AB mainly come from sputum and throat swab specimens in our hospital,and infected patients are mainly distributed in the departments of ICU and respiratory medicine. Drug resistance is serious,and the detection rate of MDR-AB is increased year by year. Main genes of multidrug-resistant strains mainly include TEM,AmpC,OXA-23,OXA-51,ant(3″)-Ⅰ, anmA,etc.,and mutation of gyrA and parC gene are found. It is necessary to strengthen the management of classification use of antibiotics and strengthen the monitoring of AB drug resistance. According to the results of drug sensitivity test,antibiotics are selected rationally to prevent or delay planting and cross transmission of AB-resistant strain.

Objective To investigate the molecular characteristic of fluoroquinolone resistant Streptococcus agalactiae (GBS) isolates in Suzhou.Methods Totally 46 fluoroquinolone resistant GBS strains were collected,and then subjected into PCR and two resistance genes were sequenced and their high frequency mutation sites,gyrA and parC were analysed.Results Among these isolates,the most frequent gyrA mutation was gyrA_S81L (TCA→TTA),which displayed 93.4％ (43/46) with substituted at No.81 site of amino acid from Ser to Leu.However,the most frequent parC mutation was mutated at No.79 site of amino acid from Ser to Tyr orPhe,with two mutations parC_S79Y (73.9％,34/46) and parC_S79F(17.4％,8/46).The analysis showed that the major mutation patterns are gyrA_S81L with parC_S79Y (73.9％,34/46),gyrA_S81L with parC(13.0％,6/46).Conclusion The most frequent mutations of fluoroquinolone resistant gene in Suzhou are gyrA and parC and the major mutation patterns are gyrA_S81L/parC_S79Y and gyrA_S81L/parC_S79F.

Objective To analyze the related risk factors of neonatal Streptococcus agalactiae infection and sensitivity of antibac‐terials ,in order to provide for provide evidence for the prevention and treatment of neonatal infection .Methods A total of 1 200 neonatal blood ,gastric juice ,pus specimens ,and maternal reproductive tract specimens were collected from Jan .2013 to Dec .2013 for bacterial culture and drug sensitive test .And clinical data about types of neonatal diseases ,maternal infection status ,mode of de‐livery ,medication in late pregnancy ,situation of neonatal death were retrospectively analyzed .Results A total of 80 cases of neo‐nates were infected by Streptococcus agalactiae ,,and the neonates diagnosed with septicemia ,omphalitis ,premature birth ,intrau‐terine infection and aspiration pneumonia were accounted for 8 .75% ,10 .00% ,15 .00% ,22 .50% and 43 .75% ,respectively .The positive rate of Streptococcus agalactiae infection in mother′s reproductive tract specimens was 51 .25% ,and the results of drug sensitive test were consistent with those of neonates .9 cases of cesarean section ,accounted for 11 .25% ;71 cases of natural child‐birth ,accounted for 88 .75% .In the 80 strains of Streptococcus agalactiae ,the sensitivity of vancomycin ,linezolid ,penicillin and ceftriaxone were all 100 .00% ,and resistance rates of Streptococcus agalactiae to erythromycin ,clindamycin and levofloxacin were higher ,and were 77 .50% ,57 .50% and 33 .75% respectively .Conclusion Maternal Streptococcus agalactiae carriers and mode of delivery may be risk factors for neonatal Streptococcus agalactiae infection .Obstetricians should pay attention to routine screening of Streptococcus agalactiae in perinatal pregnant women ,the laboratory should improve the efficacy in detecting Streptococcus aga‐lactiae and provide the results of antibacterials resistance of Streptococcus agalactiae immediately ,in order to provide references for clinical rational drug use .

Objective To investigate the clinical distribution of carbapenem-resistant Enterobacteriaceae(CRE)strains separated in this hospital and the situation of its production of carbapenem enzyme.Methods The production of carbapenem enzyme by CRE strains was confirmed by using modified Hodge test,the situation of the production of metallo-beta-lactamases by CRE strains was screened by using imipenem-EDTA double-disk synergy test,and the clinical distribution of CRE strains was retrospectively ana-lysed.Results 37 strains of CRE isolated in this laboratory were screened by using instrument method and verified by using disk diffusion (K-B)method.It showed an increasing trend from 2012 to 2014 in the amount of CRE strains.In terms of bacterial spe-cies,K.pneumonia(1 6 strains)was the main kind of carbopenems-resistant strains,followed by E.coli(6 strains),Ser.marcescens(6 strains)and E.cloacae(4 strains).CRE strains were mainly isolated from geriatric ward and intensive care unit(ICU).Sputum,u-rine and blood specimen were key sources of CRE strains.Modified Hodge test confirmed that 36 strains of CRE were the strains that can produce carbapenemase,including 4 strains of K.pneumonia,3 strains of E.cloacae,and 1 strain of E.asburiae,and strains producing metallo-beta-lactamases were confirmed by using imipenem-EDTA double-disk synergy test.Conclusion Elderly patients with underlying diseases are susceptible population of CRE hospital infection and are primary preventive targets.The principal mechanism of carbapenem-resistant CRE strains in this hospital is the production of carbapenemase and production of metallo-β-lac-tamases in a small number of strains.

Objective To review and summarize the experiences of mitral valve replacement in the children aged less than five years.Methods Twelve patients with moderate to severe mitral valve regurgitation (MR) or/and severe mitral valve stenosis (MS) were retrospectively study from January 2008 to December 2011,all of them suffered from severe heart failure and underwent mechanical mitral valve replacement.There were 9 males and 3 females.They aged from 4 to 58 months [mean (26.2 ± 18.1) months] and weighted from 5.6 to 13.0 kg [mean (9.6 ± 3.8) kg].Three patients underwent unsuccessful mitral valve repair before mitral valve replacement.17 to 23 mm aortic bileaflet mechanical prosthesis were reverse directional implanted in nine patients and 25 to 27 mm mitral bileaflet mechanical prosthesis were implanted in three patients.Results One patient died,the operative mortality rate was 8.3％.2 patients were complicated by cardiac arrhythmia and 2 patients complicated by mild hemolysis,all recovered after symptomatic treatment.The heart function of servived 11 patients improved significantly,none of them were complicated by haemorrhage or thromboembolic.Conclusion Severe mitral valve lesion injure heart function significantly for the young children and timely surgical intervention is the only option.Mitral valve replacement is the ultimate option for the patients failed in mitral valve annuloplasty.The introduction of aortic bileaflet mechanical prosthesis which smaller size is available and reverse directional implantation resolve the difficulty of prosthesis-patient mismatch essentially,most children with a small prosthesis has to redo mitral valve replacement with a larger size prosthesis.The compliance of permanent anticoagulation of young children is favourable and more intensively follow-up is essential to avoid the incidence of bleeding and thromboembolic.